In recent decades, automobile industry develops rapidly. An electronic pump has gradually replaced a conventional mechanical pump and is largely used in automobile heat management systems as performances of automobiles developing towards a safer, more reliable, more stable, fully-automatic and intelligent, and environmental friendly and energy saving trend. The electronic pump has advantages of no electromagnetic interference, being efficient and environmental friendly and capable of being adjusted continuously etc., which can meet the requirements of market well.
A stator assembly and a rotor assembly of an electronic pump are completely isolated by a partition, which avoids an issue of liquid leakage occurred in a conventional motor type brushless direct current pump. Currently, the rotor assembly of the electronic pump includes an impeller and a rotor, the rotor assembly is an integrally formed member, i.e., the impeller and the rotor are injection-molded by the same material, which wastes the magnetic material. Further, for the rotor assembly in the same series having different hydraulic characteristics, a new mold is required to be made to manufacture the whole rotor assembly, which is expensive and needs a long period of time.
Thus, it is necessary to improve the conventional electronic pump in order to address the above technical issues.